Caster



Aug. 13, 1929. R. s. KIRKPATRICK CASTER Filed May 2, 1927 Patented Aug. 13, 1929 Um'rso mm ROBERT S. KIRKPATRICK, OF DES MOINES, IOWA.

OASTER.

Application filed May 2, 1927. Serial No. 188,303.

The object of my invention is to provide a caster of simple, durable and inexpensive construction which may be formed of sheet metal by the stamping process, and which is particularly adapted to fit cylindrical supports, having 7 means whereby the supported load will cause the caster frame to be supported rigidly within the casing.

My invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which Figure 1 is an elevation of the lower end of a sup-port showing the manner in. which my caster is applied thereto.

Figure 2 is a sectional view of the support and the caster casing.

Figure 3' is a detail, sectional View taken on the line 3-3 of Figure "2.

Figure 4 is a detail sectional view taken on the line 44 of Figure 2.

Figure 5 is a detail sectional View of a modified form of the upper end of the caster casing.

My improved caster comprises a stem 10 having a fork 11 on its lower end in which is mounted a caster wheel12. The stem 10 is designed to be rotatively mounted in a caster casing comprising a sheet metal plate 13 formed circular and provided with upwardly extending members 14. The upper ends of the members 14 terminate in clownwardly and inwardly extending portions 15. The plate 13 is designed to support a disk 16 provided with openings 17 through which the members 14 project. The center of the disk 16 and the plate 13 has openings 18 through which the stem 10 of the caster projects. The upper end of the stem 10 is provided with a cone shaped cap 19 designed to rest beneath the inwardly projecting members 15, in such a manner that the weight of the members 14 is carried by the cone and the upper end of the stem.

The members 14 are designed to be placed within the cylindrical support 20, the lower end of which is designed to rest on the disk 16 in the manner clearly illustrated in Figure 2, the support 20 forming the leg of the article to be supported by the caster. The members 14 are curved, as illustrated in Figure 4, so their outer surfaces will fit the inner surfaces of the support 20. It will be seen that the weight of the support 20 will rest on the disk 16, which in turn will be carried by the plate 13, the supports 14 and the cone 19, said cone resting on the upper end of the stem 10, the upper end of said stem being rounded to form a pivot. The pivot end of the stem is supported in the apex of the cone to prevent lateral movement of the upper end of the stem, as the caster is moved over the floor.

It will further be seen that on account of the members 15 resting on the inclined upper surface of the cone 19, a considerable tendenoy will develop toward forcing the upper ends of the members 14 outwardly, to cause them to frictionally engage the inner surface of the support 20, thereby providing means for rigidlysupporting the caster casing within the support, and at the same time permitting the casing to be easily removed if so desired, as the downward movement of the stem 10 will release the outward pressure of the members 14. The stem is retained in position within the casing by forming lugs 21 near its lower end just above the disk 16.

In Figure 5, I have shown a slightly modified form of the cone shaped cap in which the lower edge of the cone 22 is provided with an upwardly and outwardly extending flange 23 to be engaged by the members 15. The flanges 23 are formed of slightly flexible material, so that the weight applied to the members 14 will cause the said flanges 23 to assume a horizontal position, which in turn will wedge the top ends of the members 14 outwardly, on account of the angular movement of the edge flange.

Thus it will be seen that I have provided a caster of simple, durable and inexpensive construction, in which the caster casing may be formed entirely of sheet metal stampings, and which may be easily and quickly placed in position within a suitable support, and which will automatically engage the inner surface of the support when weight is applied tothe caster.

I claim as my invention:

1. In combination, a cylindrical upright support, a disk adjacent to the lower end of said support having a central opening and a series of openings in alinement with the inner surface of said support, a plate having a central opening in alinement with the opening of said disk and provided with upwardly projecting members extending through the series of openings in said disk and adjacent to the inner face of said support, the upper end of said upwardly projecting members being bent downwardly and inwardly, a caster stem extending upwardly through the central openings of said plate and said disk and centrally beyond the inwardly projecting members of said uprights, and a cone shaped cap carried by the upper end of said stem having its outer edge carried beneath the inwardly extending portions of said uprights. I

2. In combination, a hollow upright support, a caster stem projecting upwardly into said support, a caster casing within said support for guiding the stem and carrying the weight of said support, said casing being provided with laterally expandable means, and means supported by the upper end of said stem for carrying said casing and forcing said expandable members outwardly into engagement with the inner surface of said support.

3. In a device of the class described, a disk having a central opening and a series of openings arranged in circular formation concentric with the central opening, a plate having a central opening in alinement with the central opening of said disk, and supported beneath said disk, said plate having bendable members extending upwardly through the outer openings of said disk, a cone supported between the upper ends of said upright members having its apex end supported uppermost, the upper ends of said supports being turned inwardly to engage the outer edge of the upper surface of said cone, the under surface of said cone also being of conical formation, a caster stem projecting upwardly through the central openings of said disk and plate and having its upper end pivotally mounted in the apex of the under surface of said cone, means for retaining said caster stem therein, a caster wheel for the lower end of said stem.

4. A caster comprising a casing designed to rest within a hollow support and to carry the weight thereof, said casing being pro- Vided with laterally expandable means, a

caster stem projecting upwardly into said casing, means plvotally resting on the upper end of sa1d stem to carry sa1d caslng and to force said expandable means outwardly into engagement with the inner surface of said support.

ROBERT s. KIRKPATRICK. 

